Converting String to Integer and handling errors

Exceptions. example from a Well House Consultants training course
More on Exceptions. [link]

This example is described in the following article(s):
• String to number conversion with error trapping in Ruby - [link]

Source code: catcher Module: R111

about = <<'ABOUT'

The built in Integer function converts a string to an integer in a
similar way to to_i, except that it throws an exception if the input
string isn't suitable for the conversion.

Here's an example in which we have read a user input and used Integer
rather that to_i to convert it into an integer, specifically to avoid
it being silently converted into a 0 if it's invalid

ABOUT

running = true
total_so_far = 0
good_values = 0
while running
        print "Give me a number (\"end\" to end) "
        said = gets.chomp
        if said =~ /\bend\b/
                running = false
        else begin
                total_so_far += Integer(said)
                goodvalues += 1
             rescue
                puts "Sorry - not accepted"
             end
        end
end
puts "The total was #{total_so_far} in #{goodvalues} good inputs!"

__END__

Here's some sample output

92:sqs grahamellis$ ruby catcher
Give me a number ("end" to end) 4
Give me a number ("end" to end) 5
Give me a number ("end" to end) werwer
Sorry - not accepted
Give me a number ("end" to end) 3
Give me a number ("end" to end) end
The total was 12!
92:sqs grahamellis$

Learn about this subject

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* Learning to program in Ruby
* Ruby Programming
Also available on on site courses for larger groups

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